The comprehensive evaluation of regional resources and environmental carrying capacity based on PS-DR-DP theoretical model

There are many achievements on the state evaluation of resources and environmental carrying capacity. Most of the studies use the traditional analysis method together with the "Pressure-State-Response" model. This article first constructs a comprehensive evaluation framework system of regional resources and environmental carrying capacity. Then it builds the "PS-DS-DP" hexagon interactional theory model and divides the carrying capacity into three pairs of interaction forces, namely "Pressure-Support", "Destructiveness-Resilience" and "Degradation-Promotion", which correspond to resources supporting ability, environmental capacity and risk disaster resisting ability, respectively. The negative load of carrying capacity includes pressure, destructiveness and degradation, while support, resilience and promotion represent the positive ones. With the changes of the shape and area of the hexagon caused by the interaction forces, the state of regional resources environmental carrying capacity could be measured. This study figures out that the state value of carrying capacity is equal to the ratio of the positive contribution value to the negative contribution value. The regional load condition shows good if the ratio is over 1, and the bigger the better. Once the ratio is less than 1, it has to be warned. Regional carrying capacity rating standards in this paper are delimited by 4 levels: Ⅰ(≤0.30), Ⅱ(0.30-0.70), Ⅲ(0.70-0.85) and Ⅳ(≥0.85) corresponding to a lower level balance load for a region with an approximate stable state, an unstable state caused by the high speed increasing, an ideal carrying capacity of an approximate stable state, and a full load with the system collapse. A perfect state is not to reach the limit while remaining the system stable. Based on the above theoretical models and the earlier achievements, this research applies the classified-array polygon method to explore the state change of resources environmental carrying capacity of Beijing from 2010 to 2015. According to the general research hypothesis, the increasing population will add to the regional resources pressure. But Beijing's resource pressure has a slight decrease as the city's population grows, which differs from the conclusions that the city was overloaded. The result shows that Beijing is getting close to a perfect state. The state value of carrying capacity was 1.0143 in 2010 and increased to 1.1411 in 2015, suggesting that Beijing's carrying capacity turned better in 2010-2015. Compared to 2010, the negative factor forces became weakened and the positive ones continued to enhance in 2015. With the average rank value achieving 0.7025 in 2015, Beijing reached the optimal load threshold and still had space for further carrying. Finally, these results give a theoretical support for Beijing to control the population within 23 million by 2020. © 2019, Science Press. All right reserved.